Wheat



Sept. 16, 1952 G, WHEAT 2,611,073

REFLEcToR APPARATUS FOR MINERS' LAMPS 2 sHEE'rs-SHEET 1 Filed June 30.1949 Sept. 16, 1952 G. WHEAT 2,611,073

REPLECTOR APPARATUS PoR MINERSy LAMPS Filed June 5o, 1949 Y2- SHEETS-SHEET 2 Patented Sept. 16, 1952 REFLECTOR APPARA TUS FOR MINERS AMPSGrant Wheat, Marlboro, Mass., assigner to Koehler Manufacturing Company,Marlboro, Mass., a corporation of Massachusetts Application June 30,1949, Serial No. 102,327

(Cl. 24U-44.1)

' 5 Claims. 1

This invention relates to reflector apparatus for miners lamps of thetype commonly referred to as cap lamps" because they are customarilyworn on a cap or hat. The Ainvention will herein be disclosed asembodied in a lamp structure of the general type shown in my earlierPatent No. 2,312,613, granted March 2, 1943, although it is not limitedin its application to lamps of this particular construction. i

In miners lamps of the general type disclosed in said patent, areflector is mounted in a stationaryposition in the lamp chamber of theheadpiece behind the lamp bulb, and the bulb lalso is supported in asubstantially fixed position in the headpiece. In the particular lampshown in said patent the bulb is held under spring pressure against theglass front or lens which closes the forward end of the lamp chamber sothat if this front is broken the bulb will be moved forward and thecontact between the lamp and one of its supply terminals will beinterrupted, thus shutting off the ow of current to the lamp andeliminating the danger of an explosion, in the event that the accidenttakes place in an explosive atmosphere.

In order to ensure the proper focusing of the light beam delivered bythese lamps, the lamp bulbs must be so selected that the filament willbe correctly placed in the bulb so that when the bulb is in itsoperative position the filament will be located at the focal point ofthe reflector. This involves a pre-testing of a large number of bulbs inorder to select those which will satisfactorily meet the requirementsjust outlined, and this testing and selecting process is timeconsumingand expensive.

The present invention aims to devise a miners lamp in which a standardbulb can be used and the reflector can be so adjusted as to make itsfocal point coincide with the filament in the lamp bulb. -It is also anobject of this invention to produce the result just described withoutinterfering in any way with the safety feature of the headpiece, asabove described.

The nature of the invention will be readily understood from thefollowing description when read in connection with the accompanyingdrawings, and the novel features will be particularly pointed out in theappended claims.

In the drawings,

Fig. 1 is a plan view ofthe interior of a headpiece embodying featuresof this invention, the View being on a large scale;

Fig. 2 is a fragmentary, sectional view showing on a still larger scale,some of l,the features of -this invention:

Fig. 3 is a perspectiveview of the reflector removedfrom the headpiece;l

Fig. 4 is an elevation showing, in detail, the means for connectingtheadjusting devices with the edge of the reflector;

Fig. 5 is a plan view of the inner end of the cam;

Fig. 6 is a plan view showing the manner in which the edge of thereflector is notched to receive an adjusting link; and

Fig. 'l is an elevation of the detail shown in Fig. 6, all of theforegoing figures being on a large scale.

The construction shown in the drawings comprises a casing or headpiece 2essentially like that shown in the patent above referred to, except forfeatures presently to be described. In this casing 'is a lamp chambernormally closed by avglass front or lens 4 held in place by a bezel 5which is screw-threaded on to the end portion of the headpiece 2.Mounted in this chamber is van electric lamp bulb 6 of a common formsupported in a standard socket 'l which, in turn, is supported on apivoted holder 8 with which a spring is associated in such a manner asto force the holder and the lamp outwardly and to hold the bulb 6 firmlyagainstthe glass front 4. Or, the mounting for the socket may, itself,be of a resilient nature such as to produce this sameresult. Current isconducted to the lamp 6 through the socket, flows through the filament,and returns through a substantially stationary contact normally held inengagement with the end terminal of the lamp by the contact of thelatter with the lens 4. This arrangement provides an important safetyfactor, as above mentioned, becauseif the glass front 4 becomes brokenand the bulb also is broken, or if the bulb is fractured in any othermanner, the 4spring mounting of the bulb will force the socket forward,thus breaking the contact between .the end terminal of the lamp and thestationary contact.

So far as the features above described are concerned, the constructionisvessentially like that illustrated in my earlier patent.

For the purposesof this invention the reflector `Ill is supported bythree metallic straps or links Il, the upper end of each link beingshaped as shown in Figs. Band 4. That is, the link has notches in theopposite sides thereof` near its upper end so that it can slidelaterally into another notch l2, Fig. 6, formed in the margin of thereilector. The inherent stiffness and resiliency of the link hold it inits operative position while be pushed away far enough to break'itsinterlocking engagement with the reflector. Because the reflector issupported solely by these three links, the latter elements may beutilized in adjusting the reflector backward and forward relatively tothe bulb in order to focus it. Preferably the reflector is madeslightly-smallerinv outside diameter than the internal diameter of theend of the lamp chamber so that the reflector can be moved down into thechamber, when desired.

Adjustment of the reflector is made by means of three cams, oneassociated with each of the links I I. These cams are alike and one isshown in detail and much enlarged in Figs. 2A and 5. As thereillustrated, it comprises a cylindrical body I3 provided with a angedhead I4 which is notched at opposite edges, as best shown at I5 in Fig.5, to receive a spanner wrench by means of which the cam may be rotatedinthe bore formed through the lateral wall of the headpiece 2 and inwhich the body I3 fits snugly. Projecting from theinner end of this partI3, andI integral with it, is van eccentric pin I '3 which extendsthrough the horizontal slot Il, Fig. 3, formed in the base II of thelink II. A washer I8 encircles the pin IB and another washer 20, dishedas shown in Fig. 2, bears on the rst washer and is backed up by a thirdwasher 2| which is keyed at I6 to the pin I6. A screw 22 threaded into asocket 24 formed in the cam holds these parts in their assembledrelationship. It will thus be seen that when one of the cams is turnedin its bearing in the wall of the lamp chamber, it will move the link IIassociated with it inward or outward, depending upon the direction ofrotation. The other adjusting devices can be operated in the same way.Thus the reilector can be adjusted to focus the lamp very accurately.Because all of the devices are accessible from outside the headpiece,the adjustment can be made easily whenever necessary and theparts willremain in their adjusted position because of the frictional resistanceto change. Such resistance is provided by the tension washer 20, theouter margin of which is pressed against the washer I8 by the washer 2land screw 22.

While the construction shown in Fig. 2- is suitable for some designs,that shown in Fig. 1 is preferable in most cases. Here the cams I3 aremounted in bosses 25 integral with the case 2 where they are completelyprotected but still accessible. Also, corresponding bosses 26 areprovided on the inside of the case and they are shaped to receive andguide the opposite parallel edges of the bases I I of the links I I.

Thus the invention provides a construction in which the reflector caneasily be adjusted to position its focal point in the filament of thelamp, and the necessity for the laborious testing of lamps, as abovedescribed, is eliminated. Also, the adjusting devices are positionedentirely within the outside surface of the casing where they arecompletely protected and no parts of them are left projecting beyondthat surface where they might catch on the handsl or clothing of theuser.

While I have herein shown and described a preferred embodiment of myinvention, it will be evident that the invention is susceptible ofembodiment in other forms without departing from the spirit or scopethereof.

Having thus described my invention, what I desire to claim as new is:

1. A miners lamp comprising a headpiece provided with a lamp chamber, alight transmitting front platel closing the forward end of said chamber,spring means for resiliently supporting an electric lamp bulb in saidchamber against said front plate, a reector associated with said bulb toreflect light from it through said front plate, means for supporting thereilector in a positionV such that-the lamp is free to move relativelythereto, said reflector supporting means including a pluralityofveccentric adjusting devices connected with said reflector andoperable fromipointsoutside of said headpiece to adjust said reflectorrelatively to said bulb.

2. A miners lamp according to preceding claim 1, in which eachof'saideccentric adjusting devices includes al link releasably engaged with therim of said reiiector, and an eccentric element operatively connected tothe link.

3. A miners lamp according to preceding claim l, in which each of saidadjusting devices includes a slotted link releasably interlocked withthereflector and an eccentric element rotatably mountedin the wall ofsaid headpiece and associatedwithsaid link to cause its rotativemovements to movethe link and the part of the reflector to which itisconnected backward and forward in the headpiece.

4. A miners lamp according to preceding claim 1, in which each of saidadjusting devices comprises an eccentric element mounted in recessedrelationship in the wall of the headpiece for rotative movement, and alink connecting said eccentric with the lmargin of the reflector.

5. A miners lamp comprising a headpiece provided with a lamp chamberhaving a lamp therein, electrical contact means for completing anelectrical path through said lamp, a lamp socket having the lamp securedtherein, said lamp socket being resiliently mounted for movement in toand out of contact with the said electrical contact means, a front platearranged to close the forward end of said lamp chamber, said front platecooperating with the lamp socket to normally hold the lamp in contactwith the electrical means, a concave reflector member associated withthe bulb to reflect light from it,

L means for supporting the vreflector in a position such that the saidlamp socket is free to move away from the electrical contact means, saidreflector-supporting means including a plurality of slotted armsreleasably engaged with the rim of the reector, guideway means providedin the side wall of the headpiece at spaced-apart points forslidably-containing the slotted arms, and a plurality of eccentricelements rotatably mounted through the side wall of the headpiece andsaid slotted arms for axially adjusting the reector in the lamp chamber.

GRANT WHEAT.

REFERENCES CITED The following references are of record in the i'lle ofthis patent:

UNITED STATES PATENTS

